Structure of the expected mutant IκB cDNA sequence in a patient with HD. Top panel: Alignment of the expected w.t. cDNA sequence of IκB and the predicted mutant IκB sequence in primary HRS cells. A point mutation at pos 739 generates a preterminal stop. Bottom panel: Presumable structure of the resulting truncated IκB protein in primary HRS cells. The ankyrin repeats required for the interaction with NF-κB are indicated by filled boxes.